J&J: 2nd shot boosts protection for moderate-severe Covid-19 to 94 pct

Johnson & Johnson said on Tuesday that a second shot of its Covid-19 vaccine, given about two months after the first, increased its effectiveness to 94 percent in the United States against moderate to severe forms of the disease.

That compares to 70 percent protection with a single dose.

The data will help J&J make its case to US regulators for a booster shot even as...